1. Field of the Invention
The present invention relates to an impact or recoil member possessing a plurality of gas cushions which are arranged within each other, and which are activatable in sequence in response to a triggering sensor.
2. Discussion of the Prior Art
An impact member which is to be mounted ahead of the front axle of a truck as a honeycombed-like protection against being able to drive beneath the truck has become known from the disclosure of ADAC motorwelt, Vol. 7/1989, page 8. Behind a covering of plastic material, the resilient sheet metal-honeycomb construction possesses forwardly oriented rod-shaped polyhedra which as a consequence of their deformation, are intended to act shock-absorbingly with regard to an impacting mass. However, in constructions of that type, the high manufacturing requirements and the comparatively extraordinary large need for installation space are disadvantageous; moreover, also the dangers caused by the impact mass towards the end surface subsequent to the splintering apart of the plastic covering in front of the cutting edge-like surface edges of the polyhedron-honeycombs.
For passenger vehicles in the higher comfort or luxury classes, there are employed inherently stable bumpers in front of shock-absorber elements, which through their internal resiliency (in rubber-like blocks) or through their work in the displacement thereof (for piston-fluid systems) are designed to absorb and dissipate the impacting energy of a striking or impact mass. Impact or recoil cup systems (such as generally spring-rubber combinations) act in a similar manner as safety systems against crash impacts in elevator shaft structures or cableway installations.
Basically, other operating criteria must be met through air bag-safety devices for vehicle passengers. In this instance, the head and possibly also the upper torso should thereby be protected by a rapid deceleration or braking caused by an accident before striking against a structural component located in front of the person, in that a crash-sensor activates a gas generator for the inflation of a gas cushion, which then allows the striking person to sink in softly, due to a discharge of gas (through the porous casing construction or through outlet valves), and immediately thereafter collapses into itself so as to thereafter no longer obstruct the driver of the vehicle. Thereby, as disclosed in German Laid-Open Patent Appln. 38 29 368, in the interior of a gas cushion there can be arranged a further, much smaller gas cushion which remains inflated subsequent to the collapse of the large outer cushion, so as to afford again in the case of a follow-up impact, a cushioning of the body without thereby representing any impermissible obstruction.
From the disclosure of German Laid-Open Patent Appln. 38 29 617 it has become known to expand a large gas cushion by means of a limited gas volume in that it is not the entire interior space of the cushion which is inflated, but rather only the small space between a double-walled cushion casing.
Completely different from the case of such passive protection for vehicle passengers are the demands on a shock-dissipating impact member of the type under consideration herein, particularly inasmuch as, in this instance, it does not pertain to short-term soft cushioning and the immediately again thereafter effected freeing of a back-and-forth swinging body movement, but rather relates to the absorption and braking conversion of the motional energy of a striking mass possessing a high kinetic energy without the need of having to stop an excessively high shock load.